This series was founded by the "Société de Mathématiques Appliquées et Industrielles" (SMAI) with the purpose of publishing graduate-level textbooks in applied mathematics. It is mainly addressed to graduate students, but researchers and engineers will often find here advanced introductions to current research and to recent results in various branches of applied mathematics. The books arise, in the main, from the numerous graduate courses given in French universities and engineering schools ("grandes écoles d'ingénieurs"). While some are simple textbooks, others can also serve as references.